As the fuel grows in market share and political power, several green groups have launched campaigns highlighting potential problems. They raise questions about everything from how natural gas is extracted to how much of a climate benefit it offers over competitors.

"Natural gas, especially newly available unconventional gas, has the potential to dramatically shift the energy landscape in the U.S.," said Matt Watson, senior energy policy manager at Environmental Defense Fund. "Done right, it could be an important part of de-carbonizing our economy as we ramp up on truly clean energy resources. Done wrong, it could further entrench us on the losing side of the climate equation and do very real damage."

The efforts build on the buzz of Oscar-nominated "Gasland," an anti-drilling documentary. The natural gas industry, which calls many aspects of that movie erroneous, argues that the concerns of environmental groups are misplaced.

"We are proud of the extraordinary role that natural gas can play in power generation, transportation and manufacturing to advance cleaner air and improve U.S. energy security," said Dan Whitten, spokesman for America's Natural Gas Alliance, the trade group for independent companies. "Our members are committed to the safe and responsible development of this resource."

Natural gas is surging in use, pushed by record low prices for the fuel.

In 2010, natural gas constituted 24 percent of power generation, from 13 percent in 1996, according to U.S. Energy Information Administration (EIA).

EIA projects that by 2024, natural gas will drop back slightly to 21 percent because of growth in renewable power and because the price of natural gas will start to rise, making coal more competitive.

But it could be buoyed by Congress. Some are talking about including the fuel in a clean energy standard, a requirement that utilities generate a portion of their power from less polluting sources.

President Obama in his State of the Union address said he wanted the country to use 80 percent clean power by 2035. In addition to renewable sources, the White House has mentioned meeting that goal with nuclear power, coal with carbon sequestration and some natural gas.

Groups like the Sierra Club have watched that growth and natural gas's growing clout, and decided that they needed to seek more federal oversight.

"It became very evident that this was a huge, looming problem and we needed to get it right," said Bruce Hamilton, director of the Sierra Club's Global Warming and Energy Program. "We don't just want to open the floodgates [and] at the same time not address the very, very serious impacts that natural gas has on the human and the natural environments."

The Sierra Club argues that drilling for the fuel can lead to groundwater contamination and problems with leaks into homes. Natural gas drillers, the green group said, enjoy exemptions from parts of several environmental rules.

The Environmental Defense Fund (EDF) contends that there are doubts about the widely held belief that natural gas emits half the greenhouse gases of coal.

The Natural Resources Defense Council, meanwhile, is filing lawsuits against developers it believes have violated federal law. NRDC also is also lobbying for beefed-up regulation of the hydraulic fracturing technique used in some drilling.

On Thursday, the cause gets help from Hollywood. NRDC and Environmental Working Group will join "Gasland" director Josh Fox in lobbying lawmakers on the need for more drilling regulation. Mark Ruffalo, an Oscar-nominated actor, also will attend. Ruffalo lives in New York and Fox part-time in Pennsylvania in towns affected by shale gas development.

The natural gas industry said it has plenty of regulation.

"Natural gas is routinely produced safely in communities across the country," Whitten said. "This is due to the commitment of our industry to responsible development, and credit also is due to the vigilant oversight of state regulators.